The present invention pertains to circuitry for sequentially energizing a plurality of lights and, more particularly, to such circuitry possessing the capability of being programmed to provide a number of different lighting sequences.
Among the uses which are contemplated for the circuitry of the present invention are the controlling of a plurality of strings of Christmas tree lights, the controlling of lights used in commercial displays, such as store window displays, and the controlling of other decorative lighting arrangements.
To enhance the aesthetic effect of decorative and display lighting, it is often desirable to provide for the blinking or flashing of the lights. For example, it is a common practice to provide, with Christmas tree lights of the series type, for each set of series lights one bulb which includes a thermally responsive switch to cause the lights of that particular series to flash or blink. With the use of individual thermally responsive switching for each light string, however, the flashes of the individual strings are purely random relative to the other strings and it is not possible to create selected patterns or sequences in the blinking of the light strings.
Sequencing controllers which employ mechanically operated switches have been proposed for the control of multiple strings of decorative lights. Examples of such controls may be found in U.S. Pat. Nos. 2,878,424, Barker; 3,808,450, Davis Jr.; 3,862,434, Davis, Jr.; and 4,057,735, Davis, Jr. Sequencing controllers of this type, however, employ motor driven cam operated switches and are, of necessity, of fairly large size. Where the sequencing controller is used to control the lights of a Christmas tree, many people find the use of a large size control unit to be objectional as such a unit is not easily concealed and, thus, detracts from the desired decorative effect. Also, the mechanical sequencing controllers of the prior art are generally designed to provide but a single sequence for the plural light strings.
Another approach to controlling a display of decorative lighting suggested by the prior art is that disclosed in U.S. Pat. No. 3,793,531, Ferrigno. In the approach adopted in this patent, a solid-state control circuit is employed with the display lights being switched on and off by means of a Triac which is gated by means of an oscillator circuit to turn on and off at selected portions of the half cycles of a standard 60 Hz alternating current signal. Here again, however, only a limited sequence is provided. Another approach to the control of plural display lights also using solid-state circuitry is taught in the article "Solid-State Ring Counters and Chasers for Light Displays" A. A. Adem, Electronics World, September 1967, pp. 84-85. In this circuit each light or series of lights is controlled by a solid-state switching device such as a Triac or an SCR and the switching device is, in turn, gated by a stepping circuit so that the lights are triggered in a predetermined but fixed sequence. A similar sequencing controller for display lights is disclosed in U.S. Pat. No. 3,934,249, Sanjana.
It is the primary object of the present invention to provide a sequencing light controller employing solid-state circuitry and having the capability of providing a number of different sequences readily selectable by the user.
A further object of the present invention is the provision of a sequencing light controller which may be housed in a compact unit so as to be unobtrusive when used in connection with decorative displays or Christmas tree lighting.
Yet another object of the present invention is the provision of a sequencing light controller having the capability of controlling a plurality of strings or banks of lights.